How to dismount/mount a database programmatically
to dismount/mount a database, use Dismount() and Mount() methods in SYS.Database class available in %SYS namespace.
NB: the database ID is its Directory
You'll find some examples of how to dismount/mount and check if a database is mounted (Mounted=1) or not (Mounted=0), and quickly see all the attributes of a database (via zwrite)
%SYS>set db="/opt/irisapp/data"
%SYS>w ##class(SYS.Database).%OpenId(db).Mounted
1
%SYS>w ##class(SYS.Database).%OpenId(db).Dismount()
1
%SYS>w ##class(SYS.Database).%OpenId(db).Mounted
0
%SYS>w ##class(SYS.Database).%OpenId(db).Mount()
1
%SYS>w ##class(SYS.Database).%OpenId(db).Mounted
1
%SYS>zw ##class(SYS.Database).%OpenId(db)
+----------------- general information ---------------
| oref value: 3
| class name: SYS.Database
| %%OID: $lb("/opt/irisapp/data","SYS.Database")
| reference count: 2
+----------------- attribute values ------------------
| %Concurrency = 0 <Set>
| BlockFormat = 2
| BlockSize = 8192 <Set>
| Blocks = 780288
| BlocksPerMap = 62464
| ClusterMountMode = 0 <Set>
| ClusterMounted = 0 <Set>
| CurrentMaps = 13
| Directory = "/opt/irisapp/data/" <Set>
| DirectoryBlock = 3
| EncryptedDB = 0 <Set>
| EncryptionKeyID = ""
| Expanding = 0
| ExpansionSize = 0 <Set>
| Full = 0
| GlobalJournalState = 3 <Get,Set>
| InActiveMirror = 0
| LastExpansionTime = "09/06/2023 20:00:01"
| MaxSize = 0 <Set>
|MirrorActivationRequired = 0
| MirrorDBCatchup = 0
| MirrorDBCreatedNew = 0
| MirrorDBName = ""
| MirrorDBPaused = 0
| MirrorFailoverDB = 0
| MirrorNoWrite = 0
| MirrorObsolete = 0
| MirrorSetName = ""
| Mirrored = 0
| Mounted = 1
| NewGlobalCollation = 5 <Set>
|NewGlobalGrowthBlock = 50 <Set>
| NewGlobalIsKeep = 0 <Set>
|NewGlobalPointerBlock = 16 <Set>
| NumberOfConfigDB = 0
| ROReasonCode = 0
| ROReasonText = ""
| ReCreate = 0
| ReadOnly = 0 <Set>
| ReadOnlyMounted = 0
| Reinitialize = 0
| RequestSize = 0
| ResourceName = "%DB_IRISAPP-DATA"
|RunCatchupDBOnCreate = 1
| SFN = 6
| Size = 6096 <Set>
| Skeleton = 0
| SparseDB = 0
+-----------------------------------------------------
%SYS>